Production of A356―1 wt% SiC nanocomposite by the modified stir casting method

The effect of the processing parameters of the modified stir casting method, including stirring rate, stirring temperature and master powder type, on the microstructure and mechanical properties of A356-1 wt% SiC nanocomposites was evaluated. The mechanical properties were measured by room temperature tensile and compression tests and the microstructure was examined by SEM and XRD. The results showed that there was a specific stirring rate and stirring temperature at which the best mechanical properties and nanoparticle distribution in the matrix were achieved. The properties and distribution were diminished at stirring rates and stirring temperatures that were higher and lower than these particular values, respectively. These degradations were intense at a high stirring temperature and stirring rate. In addition, the use of master powder with lower volume fraction of nanoparticles brought about better mechanical properties and nanoparticle distribution for the final nanocomposites. Among different tested values for the parameters, the optimum values of stirring temperature and stirring rate were 750 C and 700 rpm, respectively.